1. Field of the Invention
The present invention relates to a method of reforming a surface of an element by changing its characteristics, properties, or the like to provide desired characteristics and properties. This method is applied to the surface of an element (the inner face, outer face, or both of the element) or the surface of an element that has been subjected to some treatment. Also, the present invention relates to any element subjected to the surface reforming treatment.
The present invention especially relates to a surface reforming method, which can be carried out to reliably reform the surface of an element such as a fiber, a particle, or a container made of an olefinic resin that is difficult to treat but is harmless to the environment, and relates to a method of manufacturing an element and a fiber having a reformed surface.
2. Related Background Art
Conventionally, though the characteristics and the properties of an element are dominated by the characteristics of its constituent material, a desired characteristic can be provided by reforming the element's surface. The desired characteristics are, for example, a reactive group having a reactive property such as hydrophobic or hydrophilic, or a group reactive with an adduct or the like.
In general, such conventional surface reforming is carried out by making the surface radical using ozone or IV, or ozone in combination with UV, and forming a chemical bond between a main component of a treatment agent and the surface. On the other hand, a desired characteristic can be obtained by attaching a treatment agent, which itself has a desired characteristic, to the element's surface without making the surface radical. In this case, the continuity is usually lacking. Especially, with respect to hydrophilic properties of an environmentally harmless olefinic resin, it is only known that an incomplete hydrophilic condition, which is insufficient for a long, continuous period, can temporarily be provided by mixing a surfactant with a hydrophobic treatment agent in the presence of a liquid.
On the other hand, an adhesive or a primer is conventionally used to form an additive layer on an element. In that regard, in order to use a primer such as a silane coupling agent which is bonded to the surface of an element only by a chemical reaction, the element has to be treated to be reactive.
As another type of a primer, similar materials to that of an element can be used to utilize the affinity to the element. As such a primer, an acid-deformed polypropylene chloride is known, and is used at the time when an upper coating layer of a polyurethane resin is formed on polypropylene. However, in the case where a primer is made of a similar material to that of the surface of an element, the element's volume increases and an additional technique is required to form a thin and uniform coating. Also, the primer cannot be supplied evenly to a fine element or to the inner parts of a porous body. Especially, the acid-deformed polypropylene chloride cannot be used in an aqueous solution, because it is insoluble in water, and the way of using it is limited.
As a result, no material has been available that is soluble in water so that it can be in an aqueous solution and can be applicable to form a thin and uniform surface reforming layer regardless of the shape of the element, even among materials different from that of the surface of an element.
The present invention is innovative and is based on new findings stemming from the examination of conventional technical standards.
Surface reforming techniques that are based solely on chemical bonding by radicalizing the surface in a conventional manner can only be used to treat an extremely narrow plane but often cannot be applied to carry out sufficient and even surface reforming of the entire spherical surface or the inner or outer surface of a tube. Further, it is especially difficult to carry out the surface reforming treatment for the inside of an element comprising a complicated, porous portion such as a sponge, fibrous composite body, and void parts among fibers.
In addition, in the case where a surfactant or the like is added to a liquid, the surface reforming of an element is not actually carried out and the specific surface characteristic is lost at the time when the surfactant is eliminated and the original characteristic of the surface itself instantaneously reappears.
Moreover, though an olefinic resin has excellent water-repelling properties, i.e., the contact angle with water is 80 degrees or greater, it is utilized in almost all fields and is applicable to a considerably wide range of uses, the surface reforming method is hardly able to provide desired and durable surface characteristics.
The present invention provides a method for reforming a surface of any element by rationally carrying out surface reforming, at first, of an olefinic resin and explicating a method for maintaining the reformed characteristic and focuses upon the use of a liquid phase treatment solution presupposing that the surface treatment is possible even for an element with a complicated shape.
The inventors have found that the balance between functional groups (e.g. hydrophilic groups) and the surface of an element to be treated is well controlled to be in a desired state by utilizing the surface energy in a relation between the surface to be treated and a polymer having the functional groups (e.g. hydrophilic groups), and that the durability of the reformed surface and the stability of the quality can further be heightened by analyzing the polymer itself.